Ontology of time

[mpc755]

The reason for the discrepancy of the spaceship clock and the earth clock is not that the spaceship clock is not at sea level. One can determine who is right in this instance because one set of observers is accelerating, and you can tell that they are not in an inertial frame.

And that is exactly what the original poster is stating is incorrect. The rate at which an atomic clock ticks has nothing to do with time. The rate at which an atomic clock ticks is certainly not more accurate in terms of determining one year has passed than where the Earth is with respect to the Sun based upon the distant stars.

 

An astronomer is on the ground and determines the location of the Earth with respect to the Sun based upon the distant stars. The astronomer gets into a spaceship which travels at incredible speeds around the Earth. The astronomer lands the spaceship, looks through a telescope, and determines the Earth is in the same location with respect to the Sun based upon the distant stars as they were at the start of the experiment and determines one year has passed. Is the astronomer correct? Of course they are.

 

Only in the absurdity of mainstream physics is an atomic clock a more accurate time piece than where the Earth is with respect to the Sun based upon the distant stars.

 

Another experiment is performed with an astronaut in a spaceship. This spaceship is circling the Earth at such a high rate of speed that the atomic clock on board the spaceship only ticks of one day has passed when a similar atomic clock on the Earth ticks off one year has passed. Do you really think only one day has passed for the astronaut on the spaceship? Do you really think if the astronaut does not drink any water while on the spaceship, where one year passes on the Earth, that the astronaut will survive? If you were the astronaut would you take enough water to last you more than a day or would you be certain that only one day would really pass simply because you are traveling at a very high rate of speed and the atomic clock you have with you implies only one day will pass?

 

Are you so confident that only one day will actually pass for you while on the spaceship and not the 365 days which pass for everyone else on Earth that you would not bring any water at all?

Edited May 28, 2011 by mpc755

[swansont]

And that is exactly what the original poster is stating is incorrect. The rate at which an atomic clock ticks has nothing to do with time. The rate at which an atomic clock ticks is certainly not more accurate in terms of determining one year has passed than where the Earth is with respect to the Sun based upon the distant stars.

 

An astronomer is on the ground and determines the location of the Earth with respect to the Sun based upon the distant stars. The astronomer gets into a spaceship which travels at incredible speeds around the Earth. The astronomer lands the spaceship, looks through a telescope, and determines the Earth is in the same location with respect to the Sun based upon the distant stars as they were at the start of the experiment and determines one year has passed. Is the astronomer correct? Of course they are.

 

Only in the absurdity of mainstream physics is an atomic clock a more accurate time piece than where the Earth is with respect to the Sun based upon the distant stars.

 

Another experiment is performed with an astronaut in a spaceship. This spaceship is circling the Earth at such a high rate of speed that the atomic clock on board the spaceship only ticks of one day has passed when a similar atomic clock on the Earth ticks off one year has passed. Do you really think only one day has passed for the astronaut on the spaceship? Do you really think if the astronaut does not drink any water while on the spaceship, where one year passes on the Earth, that the astronaut will survive? If you were the astronaut would you take enough water to last you more than a day or would you be certain that only one day would really pass simply because you are traveling at a very high rate of speed and the atomic clock you have with you implies only one day will pass?

 

Are you so confident that only one day will actually pass for you while on the spaceship and not the 365 days which pass for everyone else on Earth that you would not bring any water at all?

 

Relativity is experimentally verified, so I would have no problem not taking a year's worth of supplies on such a trip.

 

The absurdities here pertain to the lack of understanding of the word precision and the use of argument from incredulity.

[Iggy]

An astronomer is on the ground and determines the location of the Earth with respect to the Sun based upon the distant stars. The astronomer gets into a spaceship which travels at incredible speeds around the Earth. The astronomer lands the spaceship, looks through a telescope, and determines the Earth is in the same location with respect to the Sun based upon the distant stars as they were at the start of the experiment and determines one year has passed. Is the astronomer correct? Of course they are.

 

Only in the absurdity of mainstream physics is an atomic clock a more accurate time piece than where the Earth is with respect to the Sun based upon the distant stars.

 

Another experiment is performed with an astronaut in a spaceship. This spaceship is circling the Earth at such a high rate of speed that the atomic clock on board the spaceship only ticks of one day has passed when a similar atomic clock on the Earth ticks off one year has passed. Do you really think only one day has passed for the astronaut on the spaceship? Do you really think if the astronaut does not drink any water while on the spaceship, where one year passes on the Earth, that the astronaut will survive?

 

A sidereal year (the time it takes the earth to orbit once) is different as measured from the surface of the earth and as measured from a coordinate system rotating around it. Relativity does not assert that either measure is any more valid than the other. They are both correct -- they are just measures of different things. The first is a measure of proper time on the surface and the second is a measure of proper time of the astronaut.

 

To think that the measure from the surface is somehow more valid and that all other clocks are in error is to elevate earth to some universally preferred position. To think that humans do not experience time dilation (that the astronaut would really spend a year, not a day) is pretty much the same as assuming people don't follow confirmed laws of physics.

[mpc755]

Relativity is experimentally verified, so I would have no problem not taking a year's worth of supplies on such a trip.

 

The absurdities here pertain to the lack of understanding of the word precision and the use of argument from incredulity.

The absurdities here pertain to the lack of understanding where the Earth is located with respect to the Sun based on the distant stars is a more accurate clock than the rate at which an atomic clock ticks and the inability to understand the rate at which an atomic clock ticks is determined by the physical environment in which it exists.

 

A sidereal year (the time it takes the earth to orbit once) is different as measured from the surface of the earth and as measured from a coordinate system rotating around it. Relativity does not assert that either measure is any more valid than the other. They are both correct -- they are just measures of different things. The first is a measure of proper time on the surface and the second is a measure of proper time of the astronaut.

 

To think that the measure from the surface is somehow more valid and that all other clocks are in error is to elevate earth to some universally preferred position.

Not universally preferred position. A preferred position versus an atomic clock. The Earth 'ticks' according to the physical environment in which it exists. An atomic clock ticks based upon the physical environment in which it exists. An atomic clock is in a different physical environment in a GPS than it is on the Earth and ticks accordingly. The rate at which the atomic clock ticks changes because of the physical environment in which it exists.

To think that humans do not experience time dilation (that the astronaut would really spend a year, not a day) is pretty much the same as assuming people don't follow confirmed laws of physics.

And what the confirmed laws of physics have determined is the rate at which an atomic clock ticks is determined by the physical environment in which it exists. The reason why light is determined to be 'c' in all frames of reference is because of the physical effects the environment has on the measuring devices.

 

What physics mistakes as time as a dimension is the measurement of time is a physical process based on the environment in which the clock exists.

 

A large planet swings by the Earth and pushes the Earth closer to the Sun. The Earth speeds up in its orbit. It now takes the Earth three months to complete one orbit of the Sun. Do you insist one year still passes for each orbit of the Sun by the Earth or do you understand what has occurred physically in nature to cause the Earth to change its physical behavior?

 

Simply because you insist on not understanding what changes physically in nature to cause an atomic clock to tick at a different rate does not mean time has changed. And likewise, it is not time which is changing which is causing the atomic clock to tick at a different rate. It is the physical environment in which the clock exists which has changed which causes the atomic clock to change its physical behavior.

Edited May 29, 2011 by mpc755

[swansont]

The absurdities here pertain to the lack of understanding where the Earth is located with respect to the Sun based on the distant stars is a more accurate clock than the rate at which an atomic clock ticks and the inability to understand the rate at which an atomic clock ticks is determined by the physical environment in which it exists.

 

No, you need to brush up on the word "accurate." The determination of the location of the earth with respect to the distant stars is limited by observation of those stars. The accuracy of any time determination is likewise limited. Atomic clock time accuracy is at a part in 10^15 more or less. What is the level of accuracy and precision of the relative location of stars? Do you have inkling of the limitations of earth orientation measurements?

 

The physical environment in which an atomic clock ticks is carefully controlled and compensated for. The people that work on these devices work very hard to ensure this, and "inability to understand" is not a phrase I'd attach to them. For all of your ranting about relativity, you have yet to demonstrate where it fails to match predictions. All hat and no cattle.

[mpc755]

No, you need to brush up on the word "accurate." The determination of the location of the earth with respect to the distant stars is limited by observation of those stars. The accuracy of any time determination is likewise limited. Atomic clock time accuracy is at a part in 10^15 more or less. What is the level of accuracy and precision of the relative location of stars? Do you have inkling of the limitations of earth orientation measurements?

 

The physical environment in which an atomic clock ticks is carefully controlled and compensated for. The people that work on these devices work very hard to ensure this, and "inability to understand" is not a phrase I'd attach to them. For all of your ranting about relativity, you have yet to demonstrate where it fails to match predictions. All hat and no cattle.

There are two synchronized clocks on a boat in a tank of water. The rate the clocks tick is determined by the pressure exerted on them by the water. One of the clocks is dropped off the side of the boat. The deeper the clock drops the more pressure exerted on it by the water the slower it ticks. If you are unable or unwilling to understand water exists and insist it is time itself which is changing which is causing the clock to tick slower, are you correct?

 

There are two synchronized atomic clocks on an airplane. The rate the clocks tick is determined by the force exerted on and throughout them by the aether. One of the clocks is dropped out a window of the airplane. The closer the clock gets to the surface of the Earth the more force exerted on and throughout it by the aether the slower it ticks. If you are unable or unwilling to understand aether exists and insist it is time itself which is changing which is causing the clock to tick slower, are you correct?

Edited May 29, 2011 by mpc755

[Iggy]

Mpc755, if the aether is a physical entity then can you please mail me some?

 

A large planet swings by the Earth and pushes the Earth closer to the Sun. The Earth speeds up in its orbit. It now takes the Earth three months to complete one orbit of the Sun. Do you insist one year still passes for each orbit of the Sun by the Earth or do you understand what has occurred physically in nature t

 

No, that is what the OP asserted. I disagreed with that definition of a year. Have you read the thread?

[swansont]

!

Moderator Note

The hypothetical aether is not a topic of discussion here. Discussion is to be limited to the topic raised in the OP and answered by accepted physics, in accordance with the rules. mpc755, you had your chance in other threads.

Do not derail this thread further by responding to this warning

[mpc755]

The physical environment in which an atomic clock ticks is carefully controlled and compensated for.

The force of gravity is not controlled and compensated for. You have two clocks on an airplane. They both tick at the same rate. You drop one of the clocks out the window of the airplane. The closer the clock gets to the Earth the greater the force of gravity exerted towards and throughout the clock the slower the clock ticks.

 

If you cool the atomic clock to absolute zero and it begins to tick slower you understand time has not changed. You understand what occurred physically in nature to cause the atomic clock to tick slower. The force of gravity is no different.

[swansont]

The force of gravity is not controlled and compensated for. You have two clocks on an airplane. They both tick at the same rate. You drop one of the clocks out the window of the airplane. The closer the clock gets to the Earth the greater the force of gravity exerted towards and throughout the clock the slower the clock ticks.

 

If you cool the atomic clock to absolute zero and it begins to tick slower you understand time has not changed. You understand what occurred physically in nature to cause the atomic clock to tick slower. The force of gravity is no different.

 

These effects are compensated for in timekeeping. BTW, the force of gravity is not what is being compensated for in GR. So this is nothing but a straw man argument.

 

The relativistic effects that appear are separate from the environmental effects. e.g. when in motion at constant velocity, with all physical parameters identical, you can't say who is moving and who is at rest, because there is no absolute frame of reference. Time dilation will be present. It's not due to a physical effect on the clock. There is no measurement of a physical parameter that will be different in the two frames.

[mpc755]

These effects are compensated for in timekeeping. BTW, the force of gravity is not what is being compensated for in GR. So this is nothing but a straw man argument.

http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html

 

"A prediction of General Relativity is that clocks closer to a massive object will seem to tick more slowly than those located further away (see the Black Holes lecture).

 

They tick more slowly due to the increase in the force of gravity exerted towards and throughout the clock.

 

The relativistic effects that appear are separate from the environmental effects. e.g. when in motion at constant velocity, with all physical parameters identical, you can't say who is moving and who is at rest, because there is no absolute frame of reference. Time dilation will be present.

If the physical parameters are identical. They are not. The clock in the airplane and the clock on the surface of the Earth do not exist in environments with all physical parameters identical. What is not identical is the force of gravity.

 

It's not due to a physical effect on the clock.

Of course it is. The faster a clock moves with respect to the state of the space in which it exists in the slower the clock ticks. Einstein stated acceleration and gravity are one in the same. They both refer to the state of the space the matter exists in. There is no absolute frame of reference but the state of the space is determined by its connection with matter and the state of the space in neighboring places.

Edited May 30, 2011 by mpc755

[swansont]

http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html

 

"A prediction of General Relativity is that clocks closer to a massive object will seem to tick more slowly than those located further away (see the Black Holes lecture).

 

They tick more slowly due to the increase in the force of gravity exerted towards and throughout the clock.

 

 

If the physical parameters are identical. They are not. The clock in the airplane and the clock on the surface of the Earth do not exist in environments with all physical parameters identical. What is not identical is the force of gravity.

 

You will get time dilation for moving clocks even when gravity (specifically the gravitational potential) is identical.

[mpc755]

You will get time dilation for moving clocks even when gravity (specifically the gravitational potential) is identical.

Correct. When you move the clocks you are changing the state of the space in which they exist. Two previously synchronized clocks at rest with respect to the state of the space in which they exist will remain synchronized as long as they exist in the same state with respect to the state of the space in which they exist. If you move both clocks identically they will remain synchronized even though they are both now ticking at different rates then they had been previously because both clocks remain in the same state, with respect to one another, with respect to the state of the space in which they exist. If you start to move one clock and not the other, or if you move the two clocks at different speeds, even when gravity is identical, the clocks exist in space in different physical states and will no longer be synchronized. It is not time which is changing which is causing the clocks to tick at the rate they do. It is the physical state of the space in which the clocks exist which causes them to tick at the rate they do.

 

In the following video starting at 1:00 you can see the physical state of the space as determined by its connections with the Earth and the state of the space in neighboring places.

 

Edited May 30, 2011 by mpc755

[swansont]

When you move the clocks you are changing the state of the space in which they exist.

 

!

Moderator Note

That gives you a preferred frame of reference, and I will point out, AGAIN, that non-mainstream discussions have to be confined to their own thread in speculations. Critiques or answers are to be mainstream science. You do not get to advance your own theory as a response.

 

Follow the rules.

 

Do not derail this thread further by responding to this warning

 

[mpc755]

!

Moderator Note

That gives you a preferred frame of reference, and I will point out, AGAIN, that non-mainstream discussions have to be confined to their own thread in speculations. Critiques or answers are to be mainstream science. You do not get to advance your own theory as a response.

 

Follow the rules.

 

Do not derail this thread further by responding to this warning

 

The original poster stated, "Clocks keeping time at different rates is a different issue than asserting that "time itself" is an actual medium/entity which differes in each and every local inertia situation."

 

The mainstream answer is that time does change.

 

How is there supposed to be a conversation when the only accepted response is from the mainstream point of view when the question is posed "Clocks keeping time at different rates is a different issue than asserting that "time itself" is an actual medium/entity which differes in each and every local inertia situation" and the only allowed for response is the mainstream response which is "no its not" when the non-mainstream answer is, yes, you are correct, clocks keeping time at different rates IS a different issue than asserting the 'time itself' differs?

 

Why even have a 'speculations' thread when you are not allowed to speculate on mainstream physics?

 

Why even have a 'speculations' thread when any post having to do with speculations can only be responded with "That is incorrect because it is different than mainstream physics"?

 

The whole point of the original post was to understand how clocks may be able to tick at different rates and how that might have nothing to do with time itself. The answer is easy, the rate at which atomic clocks tick is determined by the state of the physical space in which they exist.

 

Your response is going to be, "that is not a mainstream response". Of course it isn't. That's the whole point. My response actually explains what occurs physically in nature to cause atomic clocks to tick at the rate they do.

[swansont]

Why even have a 'speculations' thread when you are not allowed to speculate on mainstream physics?

 

You are allowed to speculate on a topic you bring up in its own thread. You are NOT allowed to hijack others' speculations.

 

Why even have a 'speculations' thread when any post having to do with speculations can only be responded with "That is incorrect because it is different than mainstream physics"?

 

That's not an accurate characterization of the responses. Mainstream physics is mainstream because it has a lot of evidence to back it up. We require that conjecture have some sort of scientific evidence and/or model to support it, which is a much, much lower hurdle to overcome. But this is not the idle conjecture/wild supposition forum.

 

The whole point of the original post was to understand how clocks may be able to tick at different rates and how that might have nothing to do with time itself. The answer is easy, the rate at which atomic clocks tick is determined by the state of the physical space in which they exist.

 

Your response is going to be, "that is not a mainstream response". Of course it isn't. That's the whole point. My response actually explains what occurs physically in nature to cause atomic clocks to tick at the rate they do.

 

You had your chance to come up with some evidence or present a basic model. You did not. Instead, you kept handwaving, and now you keep disrupting discussions started by others. What part of "Do not derail this thread further by responding to this warning" did you not understand?

[owl]

I've been gone for an extra long holiday weekend, and just finished catching up here. I can't reply all at once, so please bear with me.

 

swansont:

Discussion is to be limited to the topic raised in the OP and answered by accepted physics.

 

Are challenges to accepted physics permissible?

Reference: The topic is "Ontology of time" in the Speculations section. Can other respondents not question the meaning of "time dilation"as part of the topic so established?, i.e.,... Must variable clock “ticking” mean, beyond doubt, that “time itself” is variable... which refers back to the basic question, “What is time?”

 

BTW, I agree with a lot of what mpg755 says, and it seems like imposing a gag rule on him just eliminates anyone here who might be an ally in sincere questioning of “mainstream science”, specifically the reification of time, the subject of this thread.

 

Among many other statements mpg755 made, with which I agree, the following is brief and simple, and seems not yet answered:

The rate at which the atomic clock ticks changes because of the physical environment in which it exists.

 

You, swansont said in another post that the physical environment was not what makes “time dilate”... as follows:

The relativistic effects that appear are separate from the environmental effects. e.g. when in motion at constant velocity, with all physical parameters identical, you can't say who is moving and who is at rest, because there is no absolute frame of reference. Time dilation will be present. It's not due to a physical effect on

the clock. There is no measurement of a physical parameter that will be different in the two frames.

 

I know that “you can't say who is moving and who is at rest,” (classical Einstein) but how does this negate the effects of the physical environment on clocks... like more or less force of gravity on them or more or less velocity as in the context of my previous posts?

 

Also, please clarify my error, if there is one, in the following inquiry above:

 

Then, when a rocket goes on a near-light-speed round trip and comes back with only five years elapsed on its clock/calendar while ten years have elapsed on earth, the "reality check" is that, in fact, there have been ten earth orbits (actual years elapsed), monitored by the above synchronized, standardized earth-based clocks. So the rocket's time keeping error will be obvious, and the absurdity of arriving back five years in earth's future will be clearly debunked... along with "time dilation."

 

On second thought, if only five years have passed on the rocket voyagers timekeepers, they should arrive back on earth five years in the past relative to my proposed standardized earth/orbital reckoning of years, not five years in the future, right? The latter would require a faster clock/calendar on the rocket, but still be just as absurd, going back to the past or into the future... same kind of sci-fi nonsense, it seems.

 

Basically my ontological question (thread topic)n has not yet been answered.

I stated it as clearly as I could as follows:

 

I'm trying to get at the ontolology of "time," like, what is "it" besides event duration between designated instants?” How do we distinguish between clocks “ticking” at variable rates and “time” elapsing at variable rates?

Or, in other words (still unanswered):

Clocks keeping time at different rates is a different issue than asserting that "time itself" is an actual medium/entity which differs in each and every local inertia situation.

PLEASE address this issue.

swansont:

Relativity is experimentally verified, so I would have no problem not taking a year's worth of supplies on such a trip.

 

I would have to agree with you here on the grounds that the human aging process, metabolism, etc, probably slows down to the same relative rate as the speeding rocket’s clock. But physical processes slowing down does not automatically mean that some “thing” time slows down... ontologically speaking.

Still trying to sort this out...

[md65536]

PLEASE address this issue.

Hasn't this issue been addressed literally trillions of times in these forums, for this issue and an essentially identical issue regarding "space" as well as "time"?

 

I'm no expert but I'll stab at it once again:

 

SR and GR deal specifically with the rate at which clocks tick. The essence of time according to GR is that time is what a clock measures. Einstein defined time (as far as he dealt with it) as what clocks measure.

 

And by clock I mean anything that measures time. A mechanical clock is a clock. A person is a clock, with their age a measurement of time. Rotting fruit can be a clock -- obviously some of these are more precise than others and some of them vary greatly depending on the environment. But here's the thing: constant velocity is not an objective aspect of the environment, yet relative velocity precisely affects the rate at which clocks tick. I'll explain what I mean: Velocity is relative, which means that if you have 2 inertial frames moving relative to each other, neither frame is "preferred", ie. neither frame can be said to be absolutely at rest while only the other is moving. Practically, what this means is that any clock you have has no absolute meaning of being at rest vs being in motion, and is therefore unable to detect any clue about such a non-existent thing, and therefore behaves the same relative to an observer in its same inertial frame whether it is at rest or moving relative to another inertial frame. Therefore, different clocks in the same inertial frame will not behave differently from each other due to relative motion vs another frame. If you have 2 otherwise identical environments, such as rocket interiors, all clocks will keep time the same in them whether moving or at rest relative to something else. (Anything that makes the frame a non-inertial frame can be an exception, so you may have clocks that "behave weird" during acceleration phases. Mechanical pendulum clocks should behave differently under acceleration. However, these cases are exceptions, and SR and GR apply to the general case, so we don't have to go into these exceptions to discuss either the consequences or the validity of SR or GR (which can deal with the exceptions anyway)).

 

In summary the choice of clocks or the mechanics of those clocks don't matter. SR/GR applies to all clocks.

 

 

 

Now, you are certainly more concerned about "what time really is" and all that, beyond "time only as measured by clocks."

But GR is NOT concerned with that.

For one thing, time as measured by clocks is ALL that GR needs, as far as being a theory.

For another thing, GR does NOT imply anything more than that about what time "is".

It would be a MISTAKE to derive a greater ontological meaning of time more than what clocks measure, from GR, because it simply does not say more about time than that.

 

And this is a mistake you've made.

If you have interpreted GR as making specific claims about time being some "thing" or whatever, something more than what clocks measure, then this is an interpretation of GR, and not a part of the central theory. Certainly, there are multiple possible interpretations of GR, and the interpretation (ontological aspects?) have not been settled. The accepted interpretation will certainly change over time (especially since it's not exactly complete, as far as I know).

 

 

Your ontological study of time transcends GR. But certainly, your interpretation of time must account for GR in one way or another if it has any chance of being correct, because GR is experimentally supported.

 

In summary: Interpret time however you may wish, but 1) you may not be able to prove that certain ontological aspects of that interpretation are correct, yet 2) if your interpretation does not agree with GR then it can probably easily be proven incorrect (unless you can experimentally prove GR incorrect). Perhaps you can consider GR's implications of time as a minimalist ontological description of time, that any other ontological interpretation must accommodate.

 

 

Assuming GR says more about time is a mistake. Asking people to explain how GR deals with your specific interpretations and misinterpretations is illogical.

Expecting GR to explain any more about time than it needs to is like demanding blood from a stone. Asking people to extract more information about time from GR is like repeatedly demanding to know the blood type of blood from a stone, and this is also illogical.

Edited June 1, 2011 by md65536

[owl]

I'm hoping that swansont will answer the questions in my last post... no hurry; I'm patient.

md65536,

I have no argument with your post on how GR and SR address time.

But the old saw that time is that which clocks measure (a tautological argument in logical terms) does not address the ontological issue which is the subject of this thread (not "time according to relativity theory.")

 

To illustrate, here is a quote from a link provided by DrRocket in the "time travel" thread. From Wikipedia on the Hafele-Keating experiment and later verification with more accurate clocks:

 

...there has been a consensus among physicists since at least the 1970s that the relativistic predictions of gravitational and kinematic effects on time have been conclusively verified.

(my bold)

...“effects on time” or “effects on clocks” is the ontological question asked as the thread topic. That is my "issue."

We all know that clocks are variable, and relativity does a fine job of correcting for that variation in all kinds of situations (like GPS info.) But it makes a lot of difference whether or not time is malleable (as in "is time travel possible?") As you said, any physical process can be considered a "clock." No problem.This is not the issue. Put two clocks in motion at different velocities or in different gravity fields and they will "tick" at different rates.

 

But compare the number of earth orbits (actual years, by the definition of what the word "year" means) to the "clocked years" on I ME's rocket, as above and the former will have observed ten orbits on the "earth orbit clock" while the latter will have recorded only five years on the rocket clock/calendar.

If relativity insists that both are correct, then relativity is wrong. The rocket clock is clearly in error because of the well known relativistic effect, but that is no problem, because the correction provided by relativity adjusts for the five year discrepancy... just like GPS adjustments, which are essential for positioning accuracy.

Edited June 1, 2011 by owl

[md65536]

But compare the number of earth orbits (actual years, by the definition of what the word "year" means) to the "clocked years" on I ME's rocket, as above and the former will have observed ten orbits on the "earth orbit clock" while the latter will have recorded only five years on the rocket clock/calendar.

If relativity insists that both are correct, then relativity is wrong. The rocket clock is clearly in error because of the well known relativistic effect, but that is no problem, because the correction provided by relativity adjusts for the five year discrepancy... just like GPS adjustments, which are essential for positioning accuracy.

The Earth orbiting the sun can be considered a clock. All clocks experience the same relativistic effects under SR/GR. Different clocks tick at different rates due to relativity*, not due to mechanical error. Yes, different clocks ticking at different rates can be considered correct.

 

 

But wait, perhaps you are right. The Earth orbiting is a really big clock, and I can see how that would make it authoritative. The solar system is our homeland. Obviously it should be treated as a privileged frame of reference, even though theory and experiment show that there is no such thing. Even if we say we accept the principles of relativity, the theory must be wrong because I still don't get it. I suggest we get the word out by spamming science forums on the internets.

 

 

Then again... in your example, every observer agrees that 10 years and 10 orbits have occurred in the Earth frame while the rocket was traveling. Some just see that happening faster than others. Everyone is still correct.

 

 

* In that sense, time can be considered somewhat malleable. If you consider "traveling forward through time at different rates" to be time travel, then time travel is an experimentally verified reality.

[owl]

Still waiting and hoping for a reply from swansont (and still practicing patience.)

Meanwhile the continuing focus on basic ontology.

swansont:

...with all physical parameters identical...

Time dilation will be present. It's not due to a physical effect on

the clock.

 

Please explain. Are not differences in gravity and velocity differences in physical parameters? In what case do two clocks 'tick' at different rates in identical physical environments?

 

One more time on my basic unanswered question:

 

“Must variable clock 'ticking' mean, beyond doubt, that 'time itself' is variable... which refers back to the basic question, What is time?”...

or in other words, how is the following wrong?...

 

"...physical processes slowing down does not automatically mean that some 'thing' time slows down... ontologically speaking."

md65536:

Different clocks tick at different rates due to relativity*, not due to mechanical error.

I have never claimed that different rates of 'ticking' are due to "mechanical error."

A year still means one earth orbit by definition and in "the real world." If ten years (orbits) elapse while the above rocket is on its journey, and it's clock says that only five years have elapsed, then its clock is in error by by five years because of the effect of relativity, extreme velocity in this cased, not because of mechanical error.

 

But wait, perhaps you are right. The Earth orbiting is a really big clock, and I can see how that would make it authoritative. The solar system is our homeland. Obviously it should be treated as a privileged frame of reference, even though theory and experiment show that there is no such thing. Even if we say we accept the principles of relativity, the theory must be wrong because I still don't get it. I suggest we get the word out by spamming science forums on the internets.

There is no need for insulting sarcasm. A deep inquiry into the meaning of time (ontology as relevant philosophy of science) is certainly not "spamming."

As swansont said above, and I agree:

... you can't say who is moving and who is at rest, because there is no absolute frame of reference.

This doesn't mean that the word "year" is now meaningless, or that all clocks everywhere are equally correct in "clocking" a year. That is why relativity makes adjustments as needed to agree on timing (as per GPS, etc.)

 

We could make one galactic revolution the standard if we knew the period precisely... or to one full Bang/Crunch cycle, maybe the largest possible cosmic physical process) but those would require very small fractions for timing relevance to life on Earth. So one earth orbit makes a lot more sense as a standard, and its fractions are already very familiar.

 

 

* In that sense, time can be considered somewhat malleable. If you consider "traveling forward through time at different rates" to be time travel, then time travel is an experimentally verified reality.

In what sense is time "malleable" if it is not some kind of "stuff," an entity? (Ontology.)..."traveling forward through" what?

If "time travel is an experimentally verified reality" then can we travel forward to the end of that horse race (from the time travel thread) and then bet on the winner? How about visiting dead ancestors before they died, or is going backward in time off limits?

 

Edit, a footnote: The rocket voyagers above will have probably "aged" only five years on their journey if their "physical processes" were slowed to half their usual rate on the journey, as was the rocket clock. This, however, is by no stretch of the imagination, "time travel."

Edited June 2, 2011 by owl

[swansont]

Are challenges to accepted physics permissible?

Reference: The topic is "Ontology of time" in the Speculations section. Can other respondents not question the meaning of "time dilation"as part of the topic so established?, i.e.,... Must variable clock “ticking” mean, beyond doubt, that “time itself” is variable... which refers back to the basic question, “What is time?”

 

Yes, challenges to accepted physics are permissible. That's often what gets posted here in speculations. But one is expected to back the challenge up with some kind of testable model, and it's even better if there were some kind of data.

 

BTW, I agree with a lot of what mpg755 says, and it seems like imposing a gag rule on him just eliminates anyone here who might be an ally in sincere questioning of “mainstream science”, specifically the reification of time, the subject of this thread.

 

The problem with what mpc755 was doing was trying to back up one conjecture with another. And we're just not interested in building those types of houses of cards. I can explain just about anything by invoking invisible pink faeries. But that won't fly, because this is a science site.

 

I know that “you can't say who is moving and who is at rest,” (classical Einstein) but how does this negate the effects of the physical environment on clocks... like more or less force of gravity on them or more or less velocity as in the context of my previous posts?

 

I think I had specifically excluded gravity from my example. You negate the effects of the physical environment my maintaining rigid environmental controls — you stabilize the temperature, for example. You shield against external magnetic and electric fields. You test to see how large these effects are, too.

 

On second thought, if only five years have passed on the rocket voyagers timekeepers, they should arrive back on earth five years in the past relative to my proposed standardized earth/orbital reckoning of years, not five years in the future, right? The latter would require a faster clock/calendar on the rocket, but still be just as absurd, going back to the past or into the future... same kind of sci-fi nonsense, it seems.

 

Discussion of past/future is a diversion from the physics.

 

Basically my ontological question (thread topic)n has not yet been answered.

I stated it as clearly as I could as follows:

 

 

Or, in other words (still unanswered):

 

Clocks keeping time at different rates is a different issue than asserting that "time itself" is an actual medium/entity which differs in each and every local inertia situation.

 

PLEASE address this issue.

 

That clocks can slow down (or speed up) owing to environmental effects is not the same as saying that all slowing is due to environmental effects. Time dilation is predicted by special relativity, and while he discusses clock synchronization in order to present some definitions, none of the derivation depends on clocks and clock mechanisms. It's a time transformation.

 

I would have to agree with you here on the grounds that the human aging process, metabolism, etc, probably slows down to the same relative rate as the speeding rocket’s clock. But physical processes slowing down does not automatically mean that some “thing” time slows down... ontologically speaking.

Still trying to sort this out...

 

If all processes slow down identically, what's the difference?

[md65536]

I have never claimed that different rates of 'ticking' are due to "mechanical error."

 

I should have omitted "mechanical". Clocks ticking at different rates due to relativity are not due to any sort of error.

 

 

Clocks ticking at different rates will not remain synchronized. GPS corrections etc involve re-synchronization of one frame's clocks to another's, not correcting for errors in time-keeping.

 

In what sense is time "malleable" if it is not some kind of "stuff," an entity? (Ontology.)..."traveling forward through" what?

If "time travel is an experimentally verified reality" then can we travel forward to the end of that horse race (from the time travel thread) and then bet on the winner? How about visiting dead ancestors before they died, or is going backward in time off limits?

It is malleable in that it is adjustable, even controllable (though neither easily nor arbitrarily, but it certainly happens as an everyday phenomena on a negligible scale). It adjusts to changing circumstances.

 

"traveling forward through time" has the same meaning as "time travel" except it is limited to change in the same direction of the arrow of time. It does not imply any extra "stuff". If the word "through" bothers you, I'll change it to "one-way time travel". If that still bothers you perhaps you can define what you mean by "time travel" in a way that doesn't evoke "stuff".

 

Going backwards is more complicated and really depends on what you mean to even begin discussing if it's possible. For example, universal time doesn't exist according to SR, so having everything go backwards in time while synchronized by all (universal) observers is impossible. An individual particle might be able to go backward in time. Some types of time travel might be possible with faster-than-light travel, which is itself impossible.

 

I would say a safe bet is that any type or meaning of "time travel" that breaks the rules of causality, is impossible.

Edited June 2, 2011 by md65536

[Iggy]

I know that “you can't say who is moving and who is at rest,” (classical Einstein) but how does this negate the effects of the physical environment on clocks... like more or less force of gravity on them or more or less velocity as in the context of my previous posts?

Please explain. Are not differences in gravity and velocity differences in physical parameters? In what case do two clocks 'tick' at different rates in identical physical environments?

Differences in gravity or differences in the "force of gravity" is indeed a difference in the physical environment. An observer in a windowless room can tell the difference between being subjected to a strong force of gravity and a weak force of gravity. However, the force of gravity is not a factor in time dilation.

 

You probably imagined that clocks in a strong gravitational field tick slower than clocks in a weak gravitational field and concluded, based on that imagining, that the force of gravity changes the physical environment in a way that affects the rate of clocks. But, you have imagined relativity and time dilation incorrectly.

 

Time dilates with gravitational potential -- not gravitational force. Two clocks which feel the same force of gravity (or no force of gravity at all) but are at different gravitational potential will tick at different rates and gravitational potential is not a physical condition of an environment. This means that the gravitational potential of a system does not affect any measurement made inside the system.

 

Let me explain what that means, because it is key. A system could be a physics laboratory. Inside the laboratory there are various types of clocks and other physics equipment -- whatever might be needed. There is no way for a physicist in this laboratory to determine the gravitational potential of the laboratory itself, because gravitational potential is not a physical environmental condition of the laboratory the way that temperature, pressure, and composition are.

 

Md65536 already explained why velocity isn't a physical condition of an environment, so I won't answer that part, I'll just point out that your question answers itself,

 

I know that “you can't say who is moving and who is at rest,” (classical Einstein) but how does this negate the effects of the physical environment on clocks... like... more or less velocity...?

If you can't tell if you are moving or if you are at rest then 'velocity' has no effect on the physical environment. If 'velocity' did have an effect on your physical environment then you could tell if you were moving or at rest.

 

But compare the number of earth orbits (actual years, by the definition of what the word "year" means) to the "clocked years" on I ME's rocket, as above and the former will have observed ten orbits on the "earth orbit clock" while the latter will have recorded only five years on the rocket clock/calendar.

If relativity insists that both are correct, then relativity is wrong. The rocket clock is clearly in error because of the well known relativistic effect, but that is no problem, because the correction provided by relativity adjusts for the five year discrepancy... just like GPS adjustments, which are essential for positioning accuracy.

I searched the thread and this is the only explanation I could find you give for why the clocks on the rocket are wrong. You explain that the rocket's clock is incorrect because it disagrees with the earth clock and the earth clock is the correct clock. A logically identical argument is that French is incorrect and English is correct because English is the correct language and French is clearly in error, but can be corrected by translating it into English.

 

Because this argument is circular and fallacious, can you give any other reasons why the clocks on the rocket and the age of the rocket twin are incorrect? Can you explain, in other words, why almost every clock in the visible universe is incorrect while our solar system correctly measures duration? I ask honestly -- is it because people live in this solar system and people get to decide these things?

[owl]

A little perspective here...

 

Subject: Ontology of Time.

Proposition: Time has been erroneously reified by relativity theory.

Discussion:

swansont:

Discussion of past/future is a diversion from the physics.

 

But it’s right on the nail-head for “ontology of time,” including the question “What slows down because of the effects of relativity?” Physical processes do for sure, but that doesn’t make time a malleable entity, some “thing” that “dilates”... the essence of this thread’s challenge.

swansont:

It's a time transformation.

 

What is time transformation but change in the rate (speeding up or slowing down) of physical processes?

s:

If all processes slow down identically, what's the difference?

 

Five years in the above example.

The rocketeers come back having only aged five years and say five years have past, but their earth-based families and friends are ten years older, and all earth inhabitants say ten years have passed.

Maybe it is irrelevant to say the whole earth population and its ten years is the “correct” elapsed time just because physical processes on the spaceship slowed to half the “normal” rate.

Maybe the word “year” has become meaningless because of relativistic effects on physical processes.

And of course for “Martians” an orbit of Mars is not an earth year. I really don’t believe that an earth year is the universal standard of time, as I’ve said a few times. It (and the “day”) is simply the event duration that all of us earthlings have in common...what “a year” means here on earth.

But as I said before, using one galactic revolution or a whole “Bang/Crunch” cycle (if true) for a time reference would result in an extremely small fraction for practical use as a standardization of time units among earthlings.

This may be enough said on the subject for my part. This thread probably belonged in the Philosophy section anyway where physicists can smugly scoff at the irrelevance of philosophy for science, and assert with full confidence that "Everything is relative," or even that "Relativity is the absolute truth, and time is in fact malleable."